Methods of manufacturing nanocomposite RF lens and radome

Abstract

A method of additively manufacturing a composite article with tuned impedance and refractive-index in three dimensions. The method includes providing a ferrite feedstock. The ferrite feedstock is loaded with ferrite particles. The method further includes depositing and curing the ferrite feedstock. Therein a composite article is formed.

What is claimed is: 
     
       1. A method for manufacturing a composite article, the method comprising:
 providing a ferrite-and-polymer feedstock loaded with ferrite ceramics; 
 depositing the ferrite-and-polymer feedstock, thereby forming the composite article, with tuned impedance and refractive index in three dimensions. 
 
     
     
       2. The method of  claim 1 , wherein the ferrite-and-polymer feedstock includes one or more of polyamide-6, polyamide-12, epoxy, tricyclodecane dimethanol dimethacrylate (TCMDA), polylactic acid, polystyrene, polyurethane, and wherein the ferrite ceramics include ferrite nanoparticles. 
     
     
       3. The method of  claim 2 , wherein the ferrite nanoparticles comprise at least 1 volume percent and up to 50 volume percent of the ferrite-and-polymer feedstock. 
     
     
       4. The method of  claim 2 , wherein the ferrite nanoparticles are sized to achieve a single magnetic domain. 
     
     
       5. The method of  claim 1  wherein the ferrite ceramics include one or more of spinel ferrite, hexaferrite, garnet, and perovskite ceramic material classes. 
     
     
       6. The method of  claim 2  wherein the ferrite nanoparticles have surface ligand functionality. 
     
     
       7. The method of  claim 1 , further comprising depositing a structural material. 
     
     
       8. The method of  claim 7  wherein the structural material comprises a thermoplastic or UV-curable polymers. 
     
     
       9. The method of  claim 1 , further comprising providing and depositing a non-loaded feedstock, the non-loaded feedstock being chemically compatible with the ferrite-and-polymer feedstock, wherein depositing the non-loaded and ferrite-and-polymer feedstocks define a local concentration change of ferrite loading thereby forming a gradient variation of the ferrite loading in the three dimensions. 
     
     
       10. The method of  claim 9 , wherein the local concentration change is greater than 1%. 
     
     
       11. The method of  claim 9  wherein the non-loaded feedstock is deposited as a patterned matrix. 
     
     
       12. The method of  claim 11 , wherein the patterned matrix has gaps that vary in size thereby increasing or decreasing the impedance. 
     
     
       13. The method of  claim 12  wherein the composite article is configured to receive electromagnetic radiation of a wavelength, and wherein the gaps are less than one-tenth of the wavelength. 
     
     
       14. The method of  claim 1 , wherein the composite article is a radio-frequency lens. 
     
     
       15. The method of  claim 1 , wherein the composite article is one or more of a radome with impedance matched to surrounding free space, a waveguide, waveguide-based transmission or receiving structure, or an antenna. 
     
     
       16. The method of  claim 1 , wherein the composite article is a curved article. 
     
     
       17. The method of  claim 1 , wherein depositing the ferrite-and-polymer feedstock comprises depositing via additive manufacturing, including one or more of including inkjet printing (IJP), fused deposition modeling (FDM), selective laser sintering (SLS), multi-jet fusion (MJF), multi jet printing (MJP), stereo lithography (SL), direct metal laser sintering (DMLS), selective laser melting (SLM), multiphoton photopolymerization (MPPP), and powder jet deposition (PJD). 
     
     
       18. The method of  claim 1 , wherein the composite article comprises an A sandwich, B sandwich, C sandwich, or hybrid sandwich. 
     
     
       19. The composite article of  claim 1 , wherein the medium is free space. 
     
     
       20. The method of  claim 7  wherein the structural material includes one or more of polyamide-12, polyamide-6, polystyrene, polyurethane, polyethylene, acrylonitrile butadiene styrene, polypropylene, tricyclodecanedimethanol diacrylate, neopentyl glycol diacrylate, diethyleneglycol diacrylate, 1,6-hexanediol diacrylate, polycarbonate, and polyetherimide. 
     
     
       21. A composite article comprising:
 a cured ferrite and polymer feedstock loaded with ferrite ceramics, wherein a distribution of the ferrite ceramics imparts to the composite article a tuned impedance and refractive index in three dimensions with respect to a medium.